This invention relates in general to the field of air distribution systems and more particularly to an air conditioning terminal unit that is constructed to diffuse conditioned air in opposite directions from an air diffuser.
Office buildings and other relative large buildings are heated and cooled by passing conditioned air through ventilation ducts that lead throughout the building. Typically, each office or other area of the building has one or more outlets through which the conditioned air enters the area. A common arrangement involves the mounting of a terminal unit above a false ceiling of the room. The terminal unit has an air diffuser which diffuses the air into the room through an outlet slot built into the false ceiling.
Each separate area of the building usually has individual temperature control which is achieved by controlling the volume of air flow through the ductwork or through the diffuser slot. Systems of this general type have achieved wide popularity due in large part to their high efficiency, low cost and overall simplicity. Cost and performance benefits result from the use of a single large heating or cooling unit for supplying a number of separate areas within the building. At the same time, individual temperature control is provided for each office or other area.
U.S. Pat. Nos. 4,312,475 and 4,331,291 disclose terminal systems that control the discharge of conditioned air by inflating and deflating air bladders which control outlets from the ventilating ducts. The condition of each bladder is in turned controlled by a pneumatic circuit that includes a feedback arrangement sensitive to the velocity of the discharging air. This type of terminal unit is highly effective in many installations because the air flow is virtually independent of the main supply pressure in the ventilating ducts. Also, accurate flow control is provided and there is no need for large pressure differentials in the system.
As previously mentioned, conventional terminal units often have an air diffuser which diffuses air into the room that is to be heated or cooled. Ordinarily, the air diffuser discharges the conditioned air in a single direction, typically downwardly along an exterior wall or window. In a situation where it is desirable to direct the conditioned air primarily to one side of the terminal unit, or more to one side than to the other side, conventional air diffusers of this type are unsatisfactory because they are capable of discharging the air in only a single predetermined pattern. For example, if there are significant heat losses through a window or exterior wall, it may be desirable to direct more heated air toward the window or wall and less toward the interior part of the room. Conventional air diffusers are unable to counteract the heat losses by splitting the air flow in this fashion, and they are thus lacking somewhat in versatility and flexibility.
The present invention is directed to an improved air conditioning terminal unit and has, as its primary goal, the provision of an air diffuser that is capable of splitting the air flow and diffusing it to opposite sides of the unit.
More specifically, it is an object of the invention to provide a terminal unit having a double slot air diffuser in which conditioned air flows in opposite directions from the two slots.
Another object of the invention is to provide a terminal unit wherein the flow through each diffuser slot is individually controlled independently of the other slot. If conditions so warrant, one of the diffuser slots can be made to discharge more conditioned air than the other slot, thus directing more air to one side of the unit than to the other side.
A further object of the invention is to provide a terminal unit of the character described in which the discharge of conditioned air through each diffuser slot is uniform along the entire length of the diffuser.
An additional object of the invention is to provide a terminal unit of the character described wherein each of the diffuser slots receives air from a different outlet in the ductwork.
Yet another object of the invention is to provide a terminal unit of the character described that is well adapted to be incorporated in conventional duct work.
A still further object of the invention is to provide a terminal unit of the character described which is simple and economical to construct and install.
In accordance with the invention, these and other objects are achieved in an improved air conditioning terminal unit. A uniquely partitioned plenum receives the conditioned air that is discharged through a pair of outlets in a ventilating duct. A double slot air diffuser is connected with the plenum and provides two side by side fuser slots which throw to opposite sides of the diffuser. Partitions in the plenum cooperate with a special baffle arrangement to direct all of the air from one duct outlet to one of the diffuser slots and all of the air from the other duct outlet to the other diffuser slot. Each duct outlet is controlled by its own air bladder and, by properly controlling the bladders, the flow of conditioned air can be split as desired between the two diffuser slots. Consequently, the flow of conditioned air to each side of the terminal unit can be adjusted in accordance with the heating or cooling requirements. Each diffuser slot is equipped with a perforated plate which equalizes the flow along the length of the slot.